SLVRSTNG06

Have a 1968 mustang with gauge problems. When ignition is turned on the gas gauge needle moves very slightly to the E postion and won't read any other level even when full. The alternator gauge doesn't seem to work at all... All other gauges work normal. Any help with this issue is appreciated.

ic237

Ohm out the gauge and sensor. The gauge should read about 12 ohms. THe fuel tank sensor should be between 73-10. 73 being empty and 10 being full.

jlg2002

It's pretty evident you have an open in the fuel tank circuit. Take the wire off of the fuel tank sender and ground it momentary to the car body - with the key to run, the fuel needle should go to full scale (beyond full).
If it does you have a bad tank unit or the tank isn't grounded properly.
If it doesn't move to beyond full, the gauge is probably bad or wire is open.

The Ammeter really doesn't move much by design on these cars. Pull the headlights on and look for a flicker in the gauge- that's about all you're going to see.
These gauges are prone to going bad as well. I'd look for an aftermarket voltmeter which is a better way of judging the health of the charging system.